title: Functional deterioration of endothelial nitric oxide synthase after focal cerebral ischemia.
abstract: Endothelial nitric oxide synthase (eNOS) dysfunction is related to secondary injury and lesion expansion after cerebral ischemia. To date, there are few reports about postischemic alterations in the eNOS regulatory system. The purpose of the present study was to clarify eNOS expression, Ser1177 phosphorylation, and monomer formation after cerebral ischemia. Male Wistar rats were subjected to transient focal cerebral ischemia. Endothelial nitric oxide synthase messenger RNA (mRNA) and protein expression increased ≈ 8-fold in the ischemic lesion. In the middle cerebral artery core, eNOS-Ser1177 phosphorylation increased 6 hours after ischemia; however, there was an approximately 90% decrease in eNOS-Ser1177 phosphorylation observed 24 hours after ischemia that continued until at least 7 days after ischemia. Endothelial nitric oxide synthase monomer formation also increased 24 and 48 hours after ischemia (P<0.05), and protein nitration progressed in parallel with monomerization. To assess the effect of a neuroprotective agent on eNOS dysfunction, we evaluated the effect of fasudil, a Rho-kinase inhibitor, on eNOS phosphorylation and dimerization. Postischemic treatment with fasudil suppressed lesion expansion and dephosphorylation and monomer formation of eNOS. In conclusion, functional deterioration of eNOS progressed after cerebral ischemia. Rho-kinase inhibitors can reduce ischemic lesion expansion as well as eNOS dysfunction in the ischemic brain.
authors.affiliation: Department of Neurology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Yagita
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kitagawa
authors.forename: Naoki
authors.initials: N
authors.lastname: Oyama
authors.forename: Toshiro
authors.initials: T
authors.lastname: Yukami
authors.forename: Akihiro
authors.initials: A
authors.lastname: Watanabe
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Sasaki
authors.forename: Hideki
authors.initials: H
authors.lastname: Mochizuki
mesh_terms: D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D015153:Blotting, Western; D004195:Disease Models, Animal; D004591:Electrophoresis, Polyacrylamide Gel; D004730:Endothelium, Vascular / Q000201:enzymology* / Q000473:pathology; D007150:Immunohistochemistry; D002546:Ischemic Attack, Transient / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D008297:Male; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000378:metabolism; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D055503:Protein Multimerization; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D047428:Protein Kinase Inhibitors; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; C049347:fasudil